应变诱导二维SnSe/SnS范德华异质结的光电性质
Strain-induced electronic and optical properties of two-dimensional SnSe/SnS van der Waals heterostructure
陈卓唯 1刘文亮1
作者信息
- 1. 湘潭大学物理与光电工程学院,湖南湘潭 411105
- 折叠
摘要
二维材料具有非常优异的性能,这使其在材料物理领域具有广泛的研究价值.该文基于第一性原理方法研究计算了单层SnSe和单层SnS以及SnSe/SnS范德华异质结的电子性质和光学性质.单层SnSe和单层SnS的带隙分别为0.95 eV和1.46 eV间接带隙半导体,而SnSe/SnS异质结的带隙为0.47 eV间接带隙半导体,带隙明显低于其单层材料.SnSe/SnS异质结与其单层材料相比,具有更优异的光学性质,其介电函数虚部和光吸收系数远远大于单层材料.该文还研究了在不同类型应变下SnSe/SnS异质结的电子性质和光学性质的变化规律.单轴应变和双轴应变能够有效地调控SnSe/SnS的光电性质.研究表明,相较于a轴应变和b轴应变,双轴应变的调控效果更为显著.在双轴应变下,SnSe/SnS异质结的能带有从间接带隙到直接带隙的转变.通过应变调控可以增强SnSe/SnS异质结的光吸收系数.该研究为获得更好的电子和光学特性的材料提供了思路.研究证明SnSe/SnS范德华异质结在光电器件领域具有潜在的应用价值.
Abstract
Two-dimensional materials have excellent properties,which makes them valuable in the field of material physics.In this paper,the electronic and optical properties of SnSe and SnS monolayers and SnSe/SnS van der Waals heterojunctions are calculated based on the first principles method.Monolayer SnSe and SnS are indirect bandgap semiconductors with a band gap of 0.95 eV and 1.46 eV,while SnSe/SnS are indi-rect bandgap semiconductors with a band gap of 0.47 eV,which is significantly lower than that of their monolayer materials.SnSe/SnS heterojunction has better optical properties than its monolayer material.The virtual part of dielectric function and optical absorption coefficient of SnSe/SnS heterojunction are much lar-ger than that of its monolayer material.The electronic and optical properties of SnSe/SnS heterojunctions under different strains are also studied.Uniaxial strain and biaxial strain can effectively regulate the photoe-lectric properties of SnSe/SnS.The results show that biaxial strain is more effective than a-axis strain and b-axis strain.The energy bands of SnSe/SnS heterojunctions change from indirect to direct band gaps under biaxial strain.The optical absorption coefficient of SnSe/SnS heterojunction can be enhanced by strain regu-lation.This study provides ideas for obtaining materials with better electronic and optical properties.The re-sults show that the SnSe/SnS van der Waals heterojunction has potential application value in the field of op-toelectronic devices.
关键词
第一性原理/SnSe/SnS异质结/应变/电子性质Key words
First principles/SnSe/SnS heterojunction/strain/electronic properties引用本文复制引用
基金项目
湖南省教育厅项目(20B580)
湖南省教育厅项目(20A500)
出版年
2024
NETL
NSTL
万方数据